JP2546237B2 - Toner manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrostatic charge image developing toner used for developing an electrostatic latent image in electrophotography and electrostatic recording, and more specifically, The present invention relates to a method for producing a novel function-separated toner suitable for a heating roll fixing method.

[Conventional technology]

Electrophotography uses a photoconductive substance such as selenium as a photoreceptor, forms an electrostatic latent image by various means, attaches toner to the latent image by a magnetic brush development method or the like, and visualizes the latent image. After transferring the toner image to a transfer material such as paper or sheet, the toner image is fixed using heat, a solvent, pressure or the like to obtain a permanent image.

The heating and melting method is most often used as a method for fixing a toner image, but this method is roughly classified into two types, a non-contact type and a contact type. It has been widely used in recent years in commercial copying machines, printers, etc. because it is excellent and capable of high-speed fixing.

[Problems to be solved by the invention]

However, this heating roll fixing method also has some disadvantages. As a particularly serious drawback, it is pointed out that the amount of energy, that is, the amount of electric power used, is considerably larger than that of the pressure roll fixing method.

Of course, the fixing image strength on the transfer material such as paper is far superior to the heating roll fixing method compared to the pressure roll fixing method, and is also excellent in the point that the paper is deformed by pressure and wrinkles are generated. Therefore, how to reduce the power consumption in the heating roll fixing method by many researchers,
In other words, how to lower the minimum temperature required for fixing the toner has been studied.

One of the most effective means for achieving this purpose is to lower the glass transition temperature of the binder resin of the toner by several tens of degrees lower than the glass transition temperature that is usually used.
However, this method has a fatal drawback that the flocking resistance and fluidity of the toner are significantly impaired.

To compensate for these drawbacks, the following two measures have been conventionally proposed.

The first measure is to adhere very fine colloidal silica, alumina, titania, etc. to the toner surface to improve the blocking resistance and fluidity of the toner. This measure did not raise the minimum fixing temperature of the toner so much, and the improvement of blocking resistance and fluidity was achieved to some extent, and it seemed to be a good measure. However, these fine particles are easily released from the toner surface even if they are subjected to heat treatment or the like in order to fuse them to the toner surface, and the photoreceptor, especially the photoreceptor whose surface is coated with an organic polymer or the like. It was found to have an adverse effect on the above. That is, when used many times, these fine particles semi-permanently adhere to the surface of the photoconductor, causing an inconvenience that causes image defects. Therefore, this measure is not a drastic solution.

The second measure is to improve the blocking resistance and fluidity by forming a continuous layer of various polymers on the toner surface. This measure has a remarkable effect of improving the blocking resistance and fluidity if the material for the continuous surface coating layer is appropriately selected, and it can be a drastic improvement measure compared to the above-mentioned method of adding fine particles, but on the other hand, this continuous surface coating layer The presence of the layer hinders the heat conduction from the surface of the heat roll to the binder resin which is the main component of the toner, and as a result, the minimum fixing temperature of the toner is considerably increased, and the purpose is to lower the original minimum fixing temperature. It has become clear that there is an inconvenience of being completely contrary.

Further, these disadvantages are common problems in the non-contact type heat fusion fixing system and the pressure roll fixing system, and improvement is desired.

The inventors of the present invention have conducted various studies and studies to improve the drawbacks of the conventional toner, and as a result, have found that the toner produced by a specific manufacturing method gives good results for eliminating the disadvantages of the toner.

Therefore, a main object of the present invention is to provide a method for producing a heat fixing toner which can fix at a lower power consumption, in other words, at a lower temperature.

Another object of the present invention is to provide a method for producing a heat fixing toner having good blocking resistance and fluidity.

Another object of the present invention is to provide a method for producing a heat fixing toner having excellent triboelectrification property, image property, life and other properties.

[Means for solving problems]

That is, the present invention provides a method for producing a toner having a high surface concentration of a low critical surface energy compound, which comprises heat treating a toner composition particle containing a resin and a compound having a lower critical surface energy than the resin. It is a thing.

It is generally known that the materials having different critical surface energies are not compatible with each other and the low critical surface energy compounds are concentrated on the surface, that is, on the outside. By applying it, it is possible to easily obtain a toner in which the vicinity of the surface has a low surface energy compound concentration higher than that of the inside, and the spontaneously coated toner thus obtained can control the chargeability and fluidity by the surface layer and It has been found to be extremely useful as a function-separated toner in combination with fixability.

The binder resin used in the present invention is a binder resin for ordinary toners, such as styrenes such as styrene, chlorostyrene and vinyl styrene; monoolefins such as ethylene, propylene, butylene and isobutylene; vinyl acetate,
Vinyl esters such as vinyl propionate, vinyl benzoate, vinyl butyrate; methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate. , Esters of α-methylene aliphatic monocarboxylic acids such as dodecyl methacrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether; and vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropenyl ketone, etc. Examples of the binder resin include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, and styrene-acrylate. Nitrile copolymer, styrene -
Examples thereof include butadiene copolymer, styrene-maleic anhydride copolymer, polyethylene and polypropylene.

Further, polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin, wax can be mentioned.

Further, as the colorant of the toner, carbon black, nigrosine dye, aniline blue, calcoil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, Rose bengal and the like can be illustrated as a typical example.

The binder resin and the colorant are not limited to those exemplified above.

 A magnetic material can also be used.

As the compound having a low critical surface energy used in the present invention, a fluorine compound or a silicon compound is suitable, and various compounds can be mentioned.

The following are mentioned as a fluorine-containing compound.
That is, a polymer containing fluorine in the main chain, for example, tetrafluoroethylene, trifluoroethylene, vinylidene fluoride, monofluoroethylene, a homopolymer such as hexafluoropropylene or these monomers and ethylene, propylene, butylene, chloride Examples thereof include copolymers with vinyl, vinylidene chloride, trifluoroethylene, and other copolymerizable unsaturated bond-containing monomers.

Polymers of monomers having fluorine in the side chain are also suitable,
In particular, a fluorinated alkyl acrylate or a fluorinated alkyl methacrylate is mentioned as a representative monomer, and specifically, acrylic acid or methacrylic acid of 1,1-
Dihydroperfluoroethyl, 1,1-dihydroperfluoropropyl, 1,1-dihydroperfluorohexyl, 1,1-dihydroperfluorooctyl, 1,1-dihydroperfluorodecyl, 1,1-dihydroperfluorolauryl, 1,1,2,2-
Tetrahydroperfluorobutyl, 1,1,2,2-tetrahydroperfluorohexyl, 1,1,2,2-tetrahydroperfluorooctyl, 1,1,2,2-tetrahydroperfluorodecyl, 1,1,2, 2-tetrahydroperfluorolauryl, 1,1,
2,2-Tetrahydroperfluorostearyl, 2,2,3,3-tetrafluoropropyl, 2,2,3,3,4,4-hexafluorobutyl, 1,1, ω-trihydroperfluorohexyl, 1 , 1, ω−
Trihydroperfluorooctyl, 1,1,1,3,3,3-hexafluoro-2-fluoropropyl, 3-perfluorononyl-
2-acetylpropyl, 3-perfluorolauryl-2-
Acetylpropyl, N-perfluorohexylsulfonyl-N-methylaminoethyl, N-perfluorohexylsulfonyl-N-betylaminoethyl, N-perfluorooctylsulfonyl-N-methylaminoethyl, N-perfluorooctylsulfonyl- N-ethylaminoethyl,
N-perfluorooctylsulfonyl-N-butylaminoethyl, N-perfluorodecylsulfonyl-N-methylaminoethyl, N-perfluorodecylsulfonyl-N-
Ethylaminoethyl, N-perfluorodecylsulfonyl-N-butylaminoethyl, N-perfluorolaurylsulfonyl-N-methylaminoethyl, N-perfluorolaurylsulfonyl-N-ethylaminoethyl, N-perfluorolaurylsulfonyl- Each ester compound such as N-butylaminoethyl may be mentioned.

The following components can be used as the component copolymerized with the fluorinated alkyl acrylate or the fluorinated alkyl methacrylate.

That is, styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene,
Alkyl styrenes such as octyl styrene, fluorostyrene, halogenated styrenes such as chlorostyrene bromostyrene, dibromostyrene, iodostyrene, and styrene-based monomers such as nitrostyrene, acetylstyrene and methoxystyrene; acrylic acid, methacrylic acid,
Addition-polymerizable unsaturated aliphatic monocarboxylic acid such as α-ethyl acrylic acid, crotonic acid, α-methyl crotonic acid, α-ethyl crotonic acid, isocrotonic acid, tiglic acid, ungeric acid, maleic acid, fumaric acid, itaconic acid , Addition-polymerizable unsaturated aliphatic dicarboxylic acids such as citraconic acid, mesaconic acid, glutaconic acid and dihydromuconic acid; the addition-polymerizable unsaturated carboxylic acids and alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol,
Butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, dodecyl alcohol, tetradecyl alcohol, hexadecyl alcohol, and other alkyl alcohols, methoxyethyl alcohol, ethoxyethyl alcohol partially alkoxylated from these alkyl alcohols. , Alkoxyalkyl alcohols such as ethoxyethoxyethyl alcohol, methoxypropyl alcohol, ethoxypropyl alcohol, benzyl alcohol,
Esters with aralkyl alcohols such as phenylethyl alcohol and phenylpropyl alcohol, alkenyl alcohols such as allyl alcohol and crotonyl alcohol, especially alkyl acrylates, methacrylic acid alkyl esters, fumaric acid alkyl esters, maleic acid alkyls Esters and the like are preferable examples; amides and nitriles derived from the addition-polymerizable unsaturated carboxylic acid; ethylene, propylene, butene,
Aliphatic monoolefin such as isobutylene; vinyl chloride, vinyl bromide, vinyl iodide, 1,2-dichloroethylene, 1,2-dibromoethylene, 1,2-diiodoethylene,
Halogenated aliphatic olefins such as isopropenyl chloride, isopropenyl bromide, allyl chloride, allyl bromide, vinylidene chloride, vinyl fluoride, vinylidene fluoride; 1,3-
Butadiene, 1,3-pentadiene, 1,3-butadiene, 2,
3-dimethyl-1,3-butadiene, 2,4-hexadiene,
Conjugated diene-based aliphatic diolephin such as 3-methyl-2,4-hexadiene; 2-vinylpyridine, 4-vinylpyridine, 2-vinyl-6-methylpyridine, 2-vinyl-
5-methylpyridine, 4-butenylpyridine, 4-pentylpyridine, N-vinylpiperidine, 4-vinylpiperidine, 4-vinylpiperidine, N-vinyldihydropyridine, N-vinylpyrrole, 2-vinylpyrrole, N
Examples thereof include nitrogen-containing vinyl-based monomers such as -vinylpyrroline, N-vinylpyrrolidine, 2-vinylpyrrolidine, N-vinyl-2-pyrrolidone, N-vinyl-2-piperidone, and N-vinylcarbazole. These can be used alone or in combination of two or more.

Further, fluorine-containing epoxy resin, fluorine-containing polyester resin, fluorine-containing silicon resin, etc. can be used.

Further, a non-polymer compound containing fluorine, such as a fluorine atom-containing alkoxysilane, a fluorine atom-containing titanium acylate, a fluorine atom-containing alkoxytitanium, a fluorine atom-containing alkoxyzirconium-containing coupling agent, a fluorine-containing coupling agent, etc. A system surfactant and other fluorine atom-containing non-polymer compounds can be used.

As the silicon compound, in addition to typical polymethylphenylsiloxane and polydimethylsiloxane, so-called modified silicon varnish modified with an alkyd resin, a phenol resin, an epoxy resin or the like can be used.

To coat the surface of a toner particle with a low surface energy compound as a coating layer or a layer containing a high concentration, a generally known microencapsulation method, for example, a polymerization catalyst is supported on the core surface, In-situ polymerization method to polymerize other monomer from the, in-house method to drop the polymer substance in the curing liquid to cure the outer wall, simple to separate the concentrated polymer layer from the water-soluble polymer solution to form the wall film on the core, Complex coacervation method, air suspension coating method in which the core is suspended in the air by the fluidized bed, and the wall material substance liquid is jet-mixed and encapsulated while rotating and flying in the air flow, high speed disc rotation type or two Introduce the core polymer solution mixture into the fluid nozzle type, pressure nozzle type atomizer,
In addition to the spray dry method of drying with hot air after adizing,
Other known interfacial polymerization methods, in-liquid drying methods, melt-dispersion methods, powder bed methods, vacuum deposition plate covering methods, and electrostatic coalescence methods can also be used. In order to uniformly coat the entire surface of the toner by these methods and encapsulate the toner, it is necessary to increase the thickness of the coating layer to some extent. Therefore, when the toner is formed into a multi-layer by the above-mentioned method, various properties of the toner, particularly the fixability are adversely affected.

On the other hand, according to the method of the present invention in which the toner composition particles are heat-treated, it is possible to uniformly form a very thin layer on the carrier surface.

The basic idea of the method for producing a toner of the present invention is to use a high temperature atmosphere to cause a compound having a lower critical surface energy than a binder resin to exist in a high concentration on a carrier surface,
The toner has both fixing ability and anti-blocking property, and facilitates functional separation such as charge control.
The coating layer is remarkably superior to the conventional method for producing a function-separated type microcapsule toner in that the thickness of the coating layer is uniform and the thickness can be reduced.

The method of the present invention can be roughly classified into the following two methods.

The first method is a method in which a toner to which a low critical surface energy compound is added is prepared by an ordinary method and then subjected to a heat treatment.

Specifically, (i) a method in which the heat treatment is carried out by leaving it in the oven at a temperature not higher than the glass transition point of the resin for a long time. (Ii) A method in which heat treatment is carried out, for example, when suspending in air using a fluidized bed, and further (iii)
There is a method of performing heat treatment using a heating spheronizer.

The second method is to perform heat treatment during the formation of toner particles to transfer the low critical surface energy compound to the toner surface.

Specifically, a resin, a low critical surface energy compound and a magnetic powder are essential components, and a mixture obtained by further adding other optional components is heated and melt mixed, and the kneaded product is not solidified, and an air flow at a relatively low temperature is obtained. It is a manufacturing method of cooling and solidifying.

〔The invention's effect〕

Since the toner according to the method of the present invention in which the composition particles containing the low surface energy compound are heat-treated to concentrate the compound on the surface has good blocking resistance and fluidity, and is extremely excellent in low-temperature fixability. It has an excellent advantage in that it has excellent powder characteristics as compared with a toner using a special additive and does not have any adverse effect on the photoreceptor or the like. Further, as compared with a toner having a normal capsule structure, it exhibits remarkably excellent low-temperature fixability and good chargeability.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following description, all parts are parts by weight.

Example 1 Styrene / n-butyl acrylate / divinylbenzene copolymer (glass transition temperature 55 ° C.) 80 parts N-perfluorooctylsulfonyl-N-ethylaminoethyl methacrylate / styrene polymer 10 parts Polypropylene wax 3 parts Carbon Black 7 parts The mixture having the above composition was kneaded in a Banbury mixer, pulverized and classified, and then left in an oven at 42 ° C. for 20 days to obtain a toner according to the present invention.

Example 2 A toner according to the present invention was obtained by treating a toner having the same composition as in Example 1 with a rolling fluidized bed at 48 ° C. for 3 hours instead of stopping heating in an oven.

Comparative Example 1 The toner having the same composition as in Example 1 was used as a reference toner without being heat-treated.

Example 3 Polyester resin (resin consisting of bisphenol A / ethylene oxide adduct, hydrogenated bisphenol A, maleic acid and having a glass transition point of 58 ° C.) 90 parts Copolymer of perfluorooctylethyl methacrylate and methacrylic acid 2 parts Carbon black 8 parts The composition of the above composition was kneaded and pulverized by a conventional method, and then heat spheroidized using a heat spheronizer to obtain a toner according to the present invention.

Comparative Example 2 A control toner was obtained without thermosphericalizing the toner of Example 3.

Comparative Example 3 10% by weight of colloidal silica (R-972, manufactured by Tegusa) was added to the toner of Comparative Example 2 to obtain a control toner.

Comparative Example 4 A toner was obtained by a conventional method with a composition obtained by removing the copolymer of perfluorooctylethyl methacrylate and methacrylic acid from the composition of Example 3, and then 50 parts of this toner was mixed with perfluorooctylethyl methacrylate. 5% by weight solution of methacrylic acid copolymer in trichlorotrifluoroethane 50
After mixing with 0 part, spray drying was performed to obtain a control microcapsule toner.

3 parts of each of the toners obtained in Examples 1 to 3 and Comparative Examples 1 to 4 was mixed with 100 parts of a ferrite carrier coated with a methyl methacrylate polymer and having an average particle size of 100 μm to prepare a developer.

This developer was subjected to a fixing and copying test using an FX-2830 machine (manufactured by Fuji Xerox Co., Ltd.).

The results are shown in the table below, and it can be seen that the toners of Examples are superior to the toners of Comparative Examples in terms of fluidity, blocking resistance and the like.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Chiaki Suzuki 1600 Takematsu, Minamiashigara City, Fuji Xerox Co., Ltd. Takematsu Works (72) Inventor Ikutaro Nagatsuka 1600 Takematsu, Minami Ashigara City, Fuji Xerox Co., Ltd. Takematsu Works (56) Reference References JP-A-56-95245 (JP, A) JP-A-60-159857 (JP, A) JP-A-59-99446 (JP, A) JP-A-54-65175 (JP, A) JP-A-57- 54948 (JP, A) JP 60-79361 (JP, A) JP 57-108860 (JP, A) JP 58-136051 (JP, A)

Claims (1)

(57) [Claims] 1. A method for producing a toner having a high surface concentration of a low critical surface energy compound, which comprises heat treating a toner composition particle containing a resin and a compound having a lower critical surface energy than the resin.